The Long and Winding Road: An Overview of the Immunological Landscape of Intracranial Meningiomas

Abstract

The role of immunotherapy is gaining ever-increasing interest in the neuro-oncological field, and this is also expanding to the management of intracranial meningioma. Meningiomas are still the most common primary adult tumor of the CNS, and even though surgery and/or radiotherapy still represent cornerstones of their treatment, recent findings strongly support the potential role of specific immune infiltrate cells, their features and genomics, for the application of personalized treatments and prognostic implications. According to the PRISMA guidelines, systematic research in the most updated platform was performed in order to provide a descriptive and complete overview about the characteristics, role and potential implications of immunology in meningioma tumors. Seventy articles were included and analyzed in the present paper. The meningioma microenvironment reveals complex immune tumor-immune cells interactions that may definitely influence tumor progression, as well as offering unexpected opportunities for treatment.

Impact of Shape Irregularity in Medial Sphenoid Wing Meningiomas on Postoperative Cranial Nerve Functioning, Proliferation, and Progression-Free Survival

“…Stronger inflammatory responses might be observed in those MSWM cases with both an irregular shape and an increased MIB-1 index compared with those MSWMs that exhibit a significantly lower proportion of cellular components of the monocytic cell lineage. Immune cell infiltration is a key feature of meningiomas, with up to 30% of the cells being immune cells, which makes the meningioma microenvironment a complex landscape of interactions between tumor and immune cells [ 69 , 70 ]. Previous studies have demonstrated an association between shape and PFS in meningiomas, but this is the first report linking increased MIB-1 labeling index to postoperative cranial nerve functioning [ 41 ].…”

The role of radiation therapy and systemic treatments in meningioma: The present and the future

“…Unfortunately, this advantage has not yet been demonstrated in the neurooncological field. The study of this aspect, and for as concerns meningiomas as well, is generating significant interest 82 for a better understanding of the immunological and genomic characteristics of the tumor immune cells infiltrating can provide applications for the development of potentially more personalized treatments. Interferon‐α (IFN‐α) belongs to a family of proteins which are physiologically produced by the cells of the immune system; in addition to antiviral, antiproliferative, and immunomodulatory activity, it is able to activate some intracellular pathways that impact cell growth and division, as well as to modulate various activities of the immune system 83 .…”

Liquid biopsy evaluation of circulating tumor DNA, miRNAs, and cytokines in meningioma patients

“…The composition and influence of meningioma's tumor microenvironment are not fully understood. Infiltration of immune cells and their polarization toward pro-tumor phenotypes are observed in higher-grade tumors (II and III) ( 17 , 18 ). In this context, studying cytokines can be of great value, particularly those that attract the cells of the immune system and those related to the immunosuppression ( 19 , 20 ).…”